Control mechanism for burners



Got. .20, 1931.. R. EVANS 1,823,551

@ENTROL MECHANISM FOR BURNER S avwewtoz attozwugs Oct. 20, 1931.. E. R. CONTROL MECHANISM EUR BURNERS .2 She ets-Sheet 2 Original Filed ///4 V m Xw&

Patented a. 20, 1931 UNITED STATES EDWIN R. EVANS, OF CHICAGO, ILLINOIS CONTROL uncmmsm roa BUBNERSI Application filed April 1, .1924, Serial This invention relates to control mechanisms for burners and relates particularly to thermostatic control systems for oil burners and the like.

i It is an object of the invention to provide a thermostatic burner control mechanism having a special application to the control of a burner to which oil is delivered by a rotative element.

A further object of the invention is to control the operation of such a rotative element in common with a combustible supply to a pilot burner auxiliary to the main burner supplied by said element.

A further object is to provide means for automatically insuring a gradual closing movement of a thermostatically controlled valve so that the delivery to a'burnerof a combustible fluid under control of said valve will be cut off when occasionarises so as to reduce said flame gradually and avoid any objectionable poppin or explosive effect such as might extinguish a pilot light.

Another object is to provide means associated with a furnace or water heater adapted to thermostatically control the same and having a provision for regulating the response to temperature changes from a point remote from said control means. It is also an object of the invention to pilot burner which is associated with a main burner having its fuel supply under a thermostatic control by maintaining'normally a small delivery of gas or the like to said pilot burner automatically temporarily increasm this delivery of gas each time that a fue supply to the main burner is established through said thermostatic control. In the drawings Figure -1 is a view in front elevation of a furnace equipped with the improved thermostatic control;

Figure 2 is an enlarged view of the control mechanism in partial section;

Figure 3 is a view similar to Figure 2'butdisclosing a simplified control mechanism, particularly applicable to a waterheater;

-Figure 4 is a view similar. to Figure 2 showing the valve in open position.

economize on the use of gas or the like by a No. 703,385. Renewed March 7, 1930.-

In these views, the reference character 1 designates a furnace which may be either of the hot air, water or steam type. As a preferred heating means for said furnace there is employed an oil burner 2 to which oil is delivered by a pipe 2? through rotationjof' a vertical tube 3 adapted to be driven by an electric motor 4. The structural features of this oil burner and its supply means are more fully disclosed in my co-pending application filed jointly with Carl M. 'Tichenoryserial No. 653,267. 5 designates an expansible an-' nularly corrugated receptacle for a liquid having a low boiling point, said receptacle being mounted upon the furnace 1 in such a location that it may respond readily to the tem-' erature of the air, hot water or steam heated y the furnace. 6 is a rod secured to the outer end of the receptacle 5 and adapted to slide in a U-shaped frame 7 the ends of which are secured to the furnace at opposite sides of said receptacle. The frame 7 carries an upstanding panel 8 upon which a knife switch 9 is pivoted, said switch controlling the cir cult 10 of. the motor 4. Upon the lower portion of the frame 7 there is mounteda valve casing 11 provided with a port 12 adapted to be closed by a valve 13 and controlling communication between the gas supply pipe" "14: and the pipe 15 which leads-to a pilot burner 16 auxiliary to the main-oil burner 2. 17 designates a restricted passage in the valve casing 11 establishing a small. but continuous supply of gas fromthe pipe 14 to the pipe '15 independently of the valve, 13. Upon the stem 18 of the va1ve13 within the casing 11 a spring 19 is coiled, urgings'aid valve to its port-closing position. The rod 6 projects outwardly beyondthe frame 7 and carries a pair of spaced collars 20 and '21, the outermost of which forms an abutment for a spring 21 coiled upon the rod 6 and abutting at its other endagainst a hollow screw 22 through which the rod 6 passes. Said screw is threaded into the outer end. of an extension 22 from the frame 7 and carries a pulley 23 around which a cord 24: or thelike carry a weight 25 and is upwardly extended makes one or moreturns.- Saidcord extends; downwardlyfrom one side of'said pulley'to The frame 7 further carries a bracket 27 having the integrally projecting arms 28 and 29. Upon the arm 28 is pivoted a three armed lever 30, 31 and 32, the arms 30 and 31 extending oppositely from the pivot of said lever, and the arm 32 being transverse to the 1 arms 30 and 31. 33 is a link which pivotally connects the arm 32 with an arm 34 having a bell crank relation to the knife switch 9. .The upper end portion of said link is longitudinally slotted as indicated at 34 to engage a pin 34 terminally provided upon the arm 34. 35 is a coiled spring extending downwardly from the end of the lever arm 30 to the end of the bracket arm 29 and extending in proximity to the pivot of the triple lever 30, 31, 32.

The outer end of the, valve stem 18 is connected by a swinging link 36 to the lever arm 31, said link being formed with a longitudinal slot 37 wherein is engaged a pin 38 carried terminally by the lever arm 31. The edge of said slot is intermediately of its length formed with a shoulder 39 which, as will be hereinafter explained, is engageable by the pin 38 for the purpose of unseating the valve 13.. 4O designates a lug terminally 4 provided upon the bracket arm 29 and carryl the ing'a pin 40 upon'which a bevelled lower edge 41 of the link 36 is adapted to ride when said link is outwardly actuated so as to swing said link upwardly about its stem engaging end to release the shoulder 39 from in 38. pon the free end of the bracket arm 29 ,there is also pivoted the bell cranklever 42, 43, the arm 42 thereof being pivotally engagedwith the outer end of the valve stem 18, and the lower arm 43 of said lever belng linked to the stem 44 of a plunger 45 operating in a dash pot 46. The plunger 45 has a port 47 opening therethrough and controlled by a check valve 48. Said plunger is furthermore formed with a bleeder passage 49.

Considering nowthe operation of the described form of the invention, it is to be understood that when the temperature of the air, hot water or steam heated by the furnace 1 is below a certain point, the receptacle 5 is contracted, the switch 9 is closed, and the positions of the various arms and levers are those shown in full lines in Figure 2. When the temperature rises beyond said predetermined point, said receptacle is expanded, the

knife switch 9 is opened. The link 36 drops of its own weight when the arm 31 is in its dash line position to engage the shoulder 39 of said link with the pin 38 of said arm. Swinging of the arm 31 from its full line to its dash line position merely permits the link 36 to drop without effecting the valve 13 which is at such times closed. Opening of the switch 9 de-energizes the motor 4 and cutsoif the fuel supply to the burner 2, thus effecting a drop in the furnace temperature. When, as a result of this reduction in temperature, the receptacle 5- contracts sufficiently to carry the spring 35 again across the pivot of the triple lever 30, 31, 32, said spring snaps the parts to their full line position. Thus the switch 9 is again closed, the motor 4 is energized, and delivery of oil to the burner 2 is renewed. As the arm 31 shifts from its dash line to .its full line position, the pin 38 acting upon the shoulder 39 carries the link 36 outwardly, unseating the valve 13. During the outer portion of this movement of said link, the bevelled lower edge 41 thereof rides upon the pin 40, swinging the link 36 upwardly about its stemengaging and until the shoulder 39 is releasedby the pin 38. When this occurs the spring 19 immediately takes effect to shift the-valve 13 toward its seat, but the dash pot 45, 46 acts through the bell crank lever 42, 43 to retard this seating movement of said valve so that a relatively large pilot flame is maintained adjacent the burner 2 for a sufficient length of time to readily ignite the renewed oil supply. By thus normally maintaining the pilot flame quite small through leakage of gas through the restricted passage 17 and enlarging said flame only momentarily when the oil supplied to the main burner is renewed, a considerable enconomy of gas is effected as compared to the usual practice of constantly maintaining the pilot flame sufficiently large to ignite the oil.

The regulation provided by the screw 22 and parts 23, 24, 25, and 26 is primarily for the purpose of making the described mechanism when desired more highly responsive to temperature changes than any other thermostat (not shown) that may exercise a control of the same furnace. Thus quite commonly a thermostat is provided in one or more of the rooms to be heated by a furnace and is electrically or otherwise connected to the furnace. When the person in charge of the furnace has occasion to leave the same for any length of time, the cord 24 and weight 25 are lowered so as to actuate the screw 22 outwardly from the furnace, relieving compression of the spring 21. Thus the described thermostatic mechanism becomes more readily responsive to temperature changes and prevents any exercise'of control by a remote thermostat. This prevents damage to the furnace in case the room wherein such remote thermostat is located is preventedifrom heating up due to a window or door being left open.

The circuit 10 is shown in Figure 1 as controlled by a second switch 49* which has projecting therefrom a control arm 49 from which an open topped vessel 49 is suspended by a c'ord 49. pipe 49 leading from a receptacle 50, a stem. 51 secured thereto, a

frame 52 guiding said stem, and collars 53 and. 54 upon a portion of saidstem projecting outwardly beyond said frame, the preceding description being applicableto all of these parts. Also there is mounted as heretofore described a valve casing 55 upon the frame 52 wherein .a valve 56 controls delivery of gas from a supply'pipe' 57 to a pipe 58 leading to aburner of a water heater.

This construction differs from that originally described iii-(that the valve 56 controls the fuel supply-tea main burner wherein a. pilot flame may be maintained by leakage by a small passage 59. As. before a bracket 60 is mounted upon the frame 52, and opposit ely extending arms 61 and 63 are mounted upon an arm 64 of said bracket. Fromthe free end of the upper arm 61 the coil spring,

65 is extended to the free end of an arm 66 upon the bracket 60., 67 a is a link connecting the arm 63 to the stem 67 of the valve 56. 1

This construction in its operation is substantially similar to the first described form of the invention, and when the water in the tank reaches a certain temperature the receptacle expands sufliciently to effect a travel of the coil spring 65 across the pivot of the double armed lever 61,, 63, whereupon saidllever snaps to the position shown in dash lines in Figure 3, permitting the valve seating spring 70 to take effect. The gas supply being thus cut off from the burner, the water in the containercools until "the resultingcontraction of the receptacle .50

, causes the spring 56 to again travel across the pivot of the lever 61, 63. Said-spring then snaps the valve 56 to an open position and renews the supply of gas or other fluid fuel to the burner. The provision of the slot 69 in the link 67 8 permits the initial slow.

travel of thelever 61, 63 from its dash-line position (Figure 3') to occur without unseating the valve 56. A

What I claim as my invention is 1., In a thermostatic control mechanism, the combination with a movable element of a thermostat movable responsive to temperature changes, of a switch controlled by said thermostat, a lever .havin'ga plurality of arms, one of which is engageable' by said movable element to rock said lever, a spring engaged with said arm extending adjacent the pivot of said lever and movable across said pivot by rocking of said lever between limiting positions thereof, and alink forming an actuating connection between another arm-of said lever and said switch.

2. In a thermostatic control mechanism, a burner, a valve controlling a supply of fuel to a point adjacent said burner, a thermostat mechanism for opening said valve, means for constantly urging said valve to closed position and a dash pot retarding the closing of the valve.

3. A thermostatic control mechanism comprising a burner, a valve controlling the delivery of fuel to a point adjacent said burner, a thermostatic mechanism for opening said valve, a spring for seating said valve independentlyof said mechanism, and means retarding the seating movement of said valve.

4. In a thermostatic control mechanism, a

burner, a valve controlling the supply delivery of fuel to a point ad acent said burner, a lever for opening said valve, a lost motion connection between said lever and thevalve, providing for a closingmovement of the valve independently of said lever, and a thermostatic means for actuating the lever to open said valve.

5. In a thermostatic control mechanism, the combination with a burner, and a valve controlling the delivery of fuel to a point.

adjacent said burner, of a lever for actuating said valve to open position, a slotted link connecting-said lever and valve, apin upon said lever engaging in the slot of said link, said s'lot having an intermediate shoulder for engagement by said pin to open the valve, means engageable with said link in the opened position of the valve for' releasing the shoulder of said link from said pin, and a spring for closing said valve.

6. In a thermostatic control mechanism, a burner, a fuel supply element for said burner, a motor driving said element, a switch conher, an abutment for saidspring movable to effect variable compression of the spring, a

weight for actuating a travel of said abutment,.and means for manually operating said abutment in the other direction.

8. In a thermostat, the combination with a member movable responusive to heat changes,

of a spring opposing movement of said member 1n one directlon, a screw threadedabut- .ment forsaid spring, and a weight for actuating the travel of said member in one direction of its movement. 7

9. In a thermostatic control mechanism, a burner, a fuel supply element for said burner, a motor driving said element, a switch controlling said motor, a valvecontrolling a trolling said motor,a valve controlling a pilot supply of fuel to the burner, a thermostat, and

means comprising a pivoted lever controlled burner, a fuel supply element for said burner,

a motor driving said element, a switch controlling said motor, a valve controlling a pilot burner, a fuel supply element for said burnsupply of fuel to the burner, a thermostat, a member reciprocated by said thermostat, and mechanical means controlled by the reciprocatory movement of said member for automatically energizing and de-energizing the motor and for actuating said pilot valve upon variation of temperature adjacent the burner.

11. In a thermostatic control mechanism, a burner, a fuel supply element for said burner, a motor driving said element, a switch controlling said motor, a valve controlling a pilot supply of fuel to the burner, a thermostat comprising an expansible element mounted adjacent said switch, and mechanical means controlled by the said thermostat element for energizing and de-energizing the motor and for actuating said pilot valve upon predetermined changes in temperature adjacent the burner, said pilot valve provided with means for supplying variable quantities of fuel to the burner.

12. In a thermostatic control mechanism, a

er, amotor driving said element, a switch controlling said motor, a valve controlling a pilot supply of .fuel to the burner, a thermo stat, and means including an element reciprocated by the thermostat andmechanically connected to the switch and to the valve for energizing and de-energizing the motor and" for actuating said pilot valve, said pilot valve provided with means for supplying variable quantities of fuel to the. burner, said thermostat element adapted to actuate said pilot valve for causing a relatively large pilot flame at the burner at times when said ther mostat control means acts to energize the said motor.

13. In a thermostatic control mechanism, a burner, a fuel supply element for said burner, a motor driving said element, a switch controlling said motor, a valve controlling a pilot supply of fuel to the burner, a thermostat comprising an expansible element I mounted adjacent said-switch, a member re- "fuel to the'bur'ner, said thermostat adapted to actuate said pilot valve for causing a relatively large pilot flame at the burner at times when said thermostat acts to energize the said motor, and a relatively small pilot flame at the burner at times when said thermostat control means acts tomaintain the motor in a de-energized condition.

14. In a thermostatic control mechanism, a

burner, a fuel supply element for said burn- .er, a motor driving said element, a switch controlling said motor, a valve controlling a pilot supply of fuel to the burner, a fluid operated expansible thermostat, and mechanical means controlled by the expansion and plementing the movement of the pilot valve.

15. In a thermostatic control mechanism, a burner, a fuel supply element for said burner, a motor driving said element, a switch controlling said motor, a valve controlling a pilot supply of fuel to the burner, a thermostat, an element reciprocated by the thermostat, a lever having a plurality of arms, one ofwhich is engageable by the reciprocating element to rock the lever, and means connecting the other arms of the lever to the switch and valve respectively, whereby rocking of the lever actuates the said switch and valve.

16. Ina thermostat, the combination with a member movable in response to heat changes, of resilient means opposing the movement of said member, threadedly adjustable means for varying the operative effort of said resilient means and means including a weight for actuating said adjustable means.

17 In a thermostat, the combination with a member movable in response to heat changes, of means opposing the movement of said member, an abutment for said opposing means adjustable to vary the operative effort thereof, means for automatically moving said abutment in one direction and manual means for moving said abutment in the other direction.

18. In a thermostat control mechanism, a burner, a valve controlling a supply of fuel to a point adjacent said burner, a thermostatic mechanism mechanically connected to said valve for opening the same, means for constantly urging said valve to closed position and means retarding the closing of the valve.

19. In a thermostat control mechanism, a burner, a fuel supply element for said burner, a motor driving. said element, a circuit including said motor and a pair of switches controlling said motor, a valve controlling a pilot supplyof fuel to the burner, means m'echanically connecting said thermostat with one of said switches and with said valve for automatically actuatin one of said switches and said valve in depen ence upon variations in temperature adjacent the burner, means adjacent said fuel supply element for collectmg unused fuel and means acting in dependence upon an accumulation of'this fuel for opening the'other of said switches.

20. In a thermostat control mechanism, a burner, an element controlling an ignition means adjacent said burner, a thermostat mechanism mechanically connected to said element for operating the same, and means for normally holding the element in an off position independently of said thermostat mechanism.

21. In a thermostat control mechanism, a burner, a valve controlling a pilot supply of fuel to the-burner, a thermostat mechanism v mechanically connected to said valve for opening the same, and means for slowly moving said valve toward closed position independentl of said thermostat mechanism.

In testimony whereof I aflix my signature.

- EDWIN R. EVANS. 

